The RC-IGBT was first fabricated and reported by Hideki Takahashi in the reference “1200V Reverse Conducting IGBT, 04 ‘ISPSD”. The principle is that the antiparallel IGBT and the diode are integrated on a single chip to realize both forward and reverse conduction (as described in FIG. 1). The RC-IGBT has advantages of effectively preventing parasitic effects generated in packaging traditional IGBT and diode and lower manufacturing cost. For the RC-IGBT shown in FIG. 2, at the beginning of the forward conduction of the device, the current flowing through the drift region is the electron current. The electron current is collected by the N-type collector region. This conduction mode is MOSFET mode. When the voltage between the collector and emitter of the device is increased so that the PN junction of the collector region (PN junction formed by the P-type collector region and the N-type field cut-off region) is turned on, a large number of holes begin to inject into the drill region to conduct a conductance modulation effect. Therefore, the forward conduction voltage of the device is significantly reduced. This conduction mode is IGBT mode. Due to the conversion from the MOSFET mode to the IGBT mode, the output characteristic curve of the conventional RC-IGBT shows a negative resistance effect (also called voltage snapback phenomenon), as shown in FIG. 3.